Expansible bit



(No Model.)

E. FORD.

EXPANSIBLB BIT. No. 525,386. Patented Sept. 4, 1894.

- means of a locking lever e.

UNITED STATES- PATENT ()FFICE.

ELLSWORTI I FORD, OF NEW HAVEN, CONNECTICUT.

EXPANSIBLE BIT.

' SPECIFICATION forming part of Letters Patent No. 525,386, datedSeptember 4, 1894.

Application filed M rch 9, 1893- Serial No. 465,230. (No modeL) To allwhom it may concern.-

Be it known that I, ELLSWORTH FORD, a citizen of the United States, anda resident of the city and county of New Haven and State ofConnecticut,have invented new and useful Improvements in ExpansibleBits, of which the followingdescription, taken in connection with thedrawings herewith accompanying, is a specification.

My invention relates to that class of bitsknown as expansible bits,which are usually provided with a stationary cutter and an ad j ustablecutter; the latter being located on a laterally sliding plate which issupported and adjustable in a suitable groove or way in the shank of thebit, in which it is adjustably loclied to hold the cutter carriedthereby in a desired position,by means of .a suitable looking device;and my present invention consists in the construction and combination ofthe several parts forming such locking device for securing theadjustable cutter, in a manner as will hereinafter be described indetail and pointed out in the claims.

The object of my invention is to provide a cheap and simple device forthe purpose above referred to, that may be easy and convenient .ofadjustment and positive in its operation.

Referring to the drawings :'-Figure 1, represents a plan view of myimproved bit, and Fig. 2, aside view of the same, partly in section.

To explain in detail,-a represents the shank of the bit,b the fixedcutter, o the gimlot, and d the adjustable cutter, which latter consistsof a plate as shown having the cutting lip or spur d thereon. This adjus'table cutter is provided with a tapering shoulder 01 on its forwardedge which is adapted to engage with a correspondingly shaped undercutshoulder a on the body of the bit, against which it is adapted to beforced and adj ustably held in a desired stationary. position by Thislocking lever 6 is hinged or pivotednpon the bit in a manner as willhereinafter be set forth, and is provided at one end with a cam surfacee, as shown in Fig. 2, which is adapted to engage with the rear edge ofthe adjustable cutter d, when the lever is properly adjusted, to forcethe cutter against the said under-cut shoulder a on the body of the bitand securely lock the same in a desired position, as will be readilyunderstood. The levene 1s adjusted or operated to act upon the ad ustable cutter as described, by means of an adjusting-screw f which islocated in the bit in a position, as shown in Fig. 2, to engage at oneend with the under side of the lever e and be operated from that side ofthe bit opposite the lever e. be operated to act upon the adjustablecutter with any required degree of pressure and be held in such positionby its said operating screw f. The lever e, in the present in- The camlever e may thus stance shown,is provided with atransversely arrangedshoulder a on its under side having an inwardly tapering and slightlyrounded or curved surface, which is adapted to engage with acorrespondingly shaped shoulder on the bit, on which latter the lever isadapted to hinge or pivot for its operation as before described. Thelever is held in position on the bit by a screw a The connection betweenthe parts being somewhat loose in order to allow for the proper movementof the 7 5 lever. This described form of pivotal connection between thelever e and the bitI consider the most desirable for strength andsimplicity, although it is obvious that it may be otherwise hingedwithout departing from the various modifications might be made without 9departing from the spirit of my invention, but

What I claim, and desire to secure by Letters Patent of the UnitedStates, is-

. 1. In an expansible-bit, the combination I with the adjustable cutter,of a centrally pivoted rocking lever provided with a cam surface at oneend for engaging with said adj ustable cutter, and with a shoulder onits under side adapted to engage with an opposing IOO- shoulder on thebit on which the lever pivots andhas its bearing, and means for engagingthe opposite end of said lever to adjust the forth.

3. In an expansible bit, the combination with the adjustable cutter, ofa pivoted lever adapted to engage at one end with said adjustablecutter, provided with a shoulder thereon adapted to engage withashoulder on the bit, on which the lever pivots and has its bearing, ascrew connecting said lever with the bit at the point of its pivotalconnectlon with the latter, and means for adjusting the lever,substantially as and for the purpose set forth.

'ELLSWORTH FORD.

Witnesses:

JAMES BISHOP, GEO. R. COOLEY.

